ATT&CK coverage › Technique

Modify Authentication Process: Password Filter DLL T1556.002

Adversaries may register malicious password filter dynamic link libraries (DLLs) into the authentication process to acquire user credentials as they are validated.

Events covered

3 catalog events are tagged with this technique by at least one rule.

ProviderEvent IDTitle
Sysmon1Process creation
Security-Auditing4688A new process has been created.
PowerShell4104Creating Scriptblock text (MessageNumber of MessageTotal).

Authoring guide

Patterns shared across the 3 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (4 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

FieldRulesHowSample values
CommandLine2match 2scecli\0*, HKLM\SYSTEM\CurrentControlSet\Control\Lsa, reg add, /cfg, /export
Image1ends_with 1\secedit.exe
OriginalFileName1eq 1SeCEdit
ScriptBlockText1regex_match 1(Copy-Item|cpi) .{2,128} -Destination...

Top indicator values (10 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique.

FieldKindValueRules (here)Corpus reach
CommandLinematchscecli\0*1
CommandLinematchreg add1
CommandLinematchHKLM\SYSTEM\CurrentControlSet\Control\Lsa1
CommandLinematch/configure1
CommandLinematch/db1
OriginalFileNameeqSeCEdit1
CommandLinematch/cfg1
Imageends_with\secedit.exe1
CommandLinematch/export1
ScriptBlockTextregex_match(Copy-Item|cpi) .{2,128} -Destination .{1,32}\\Windows\\(System32|SysWOW64)1

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Sigma 3 rules